Motion-picture projector



Dec. 14, 1948. w R. A. CLAPP 2,455,913

uo'ndu PICTURE Pnomcmon I Filed June 23, 1945, 4 Sheets-Sheet 1 INVENTOR. ROY A. v CLAPP.

"fad, PJY )kw AT TOR N 5Y8 Dec. 14, 1948. CLAPR 2,455,918

MOTION PICTURE PROJECTOR ATTOR N EYS.

. 'Dec. 14,1948.

Filed June 23. 1945 R. A. CLAPP IOTION PICTURE PROJECTOR 4 Sheets- 5km. 4

- INVENTOR'. ROY A. CLAPP.

full, WM! 1 WM ATTORNEYS.

Patented Dec. 14, 1948 UNITED STATES PATENT OFFICE MOTION-PICTURE PROJECTOR Application June 23, 1945, Serial No. 601,091

Claims. 1

This invention relates to improvements in motion picture projectors and more particularly to improvements in mechanisms of the intermittent feed type which are capable of ready manufacture at economical cost, easy servicing, and replacement of parts. More particularly the invention relates to improvements in the frame and mechanism construction permitting the film feeding mechanism to be removed and replaced or repaired as a unit.

It is also an object of the invention to provide a unit construction film feeding mechanism which may be assembled or disassembled as a unit from a motion picture projector.

Other and further objects of the invention are those inherent in the apparatus herein illustrated, described and claimed.

The invention is illustrated with reference to the drawings in which Figure 1 is a fragmentary side elevational view of a motion picture projector showing the unit construction from the left side;

Figure 2 is a, fragmentary front elevational view of the apparatus of Figure 1 in place on the projector and also showing the film feed sprockets, lens block and sound roller;

Fig ure 3 IS a fragmentary sectional view taken along the lines 3- 3 of Figure 1;

Figure 4 is a fragmentary front sectional view taken along the lines 4-4 of Figure 1;

Figure 5 is a side elevational view of the subassembly frame as it appears when removed from the projector;

- Figure 6 is a fragmentary front elevational view with the film feed sub-assembly removed;

Figure 7 is a front elevational view of the film feed sub-assembly as removed from the machine;

Figure 8 is a fragmentary side elevational view of the central vertical frame member of the projection apparatus; and

Figure 9 is a sectional view of one of the sprocket shaft drive gears.

Referringto the drawings the projector main frame generally designated I0 includes a central vertical panel ii arranged longitudinally of the machine in the fore and aft (projecting direction and a central transverse stiffening and housing panel l2. The vertical panel Ii is provided with a cut-out portion i3 as shown in Figure 8 and is provided with a plurality of threaded apertures H for receiving the sub-assembly attachment screws and two apertures 46' and 41 for receiving and aligning the sprocket shaft bushings as hereinafter described.

Referring to Figures 2, 4 and 6 to the right hand side of the main frame panel .II as viewed in the projection direction, (and at the left hand side, as shown in the drawings) there are provided film feeding sprockets l5 and I! which are mounted and driven as "hereinafter described. Adjacent sprocket I5 is a guide roll l8 and adjacent sprocket I 1 is a guide roll i9. Above the sprocket I5 is a film guide and clamping arrangement generally designated 20. A similar film guide and clamp generally designated 2| is shown adjacent sprocket i'l. Between sprockets l5 and I1 there is provided a removable lens block 22, which is held in place by thumb screws 24 and 25 which are threaded into the central frame panel I l as shown in Figure 4. provided with a focusing arrangement generally designated 26 which is provided with a frictional detent 21.

The sprocket I 1 when rotated at a uniform rate serves to feed film F through the raceway 28 from which it is withdrawn at a uniform rate by the sprocket I5.

On the left-hand side of the panel I I, as viewed in the projecting direction (to the right as shown in Figures 2, 4 and 6), there is mounted a subassembly generally designated 30, shown in Figure 7, which is the drive for intermittently feeding the film, step-by-step, through the raceway and also for rotating the sprockets 15 and I! at a uniform rate, all for progressing the film through the projecting apparatus. As shown in Figure '7, the film feeding sub-assembly includes a sub-frame member generally designated 3i having the shape and configuration shown in Figure 5. 'The frame 3i has a finished, fiat mounting surface at the left, as shown in Figure 7, and has three mounting lugs 32 provided with holes 33 located as to overlie the threaded holes M in the frame panel H, Figure 8.

The sub-assembly frame 3|, having opening 35 therein for alignment with opening l3, see Figures 1, 3, 5 and '7, includes a pair of split bearing supports 36 provided with threaded holes 38 for receiving the retaining screws 39, Figure 7, which hold the bearing retaining cap 40 in place. A high quality ball bearing 4| may thus be clamped in place in each bearing support 36. The subassembly frame 3! is also provided with a plurality of stiffening webs 42 and with a pair of apertures 44 and 45 into which there are pressed the bearing metal bushings 4S and 41, respectively, as shown in Figures 3 and 4. It may be noted that the bushings and 41 protrude through locating apertures 46' and 41, respectively, in the vertical frame panel ii when the sub-assem- The lens block is bly is in place thereon. The bushings 4G and 4! thus serve as very accurate locating pins for readily locating the sub-assembly frame and in. addition serve as hearing supports for a pair of sprocket shafts, as hereinafter described. The bushings 46 and ii are located equal distances above and below the center line 48-48, Figure 5. The sub-assembly frame, Figures 3 and 5, is also provided with a pair of vertical v notches 49 and 50 which are vertically aligned, and. at the side of each V notch there are a pair of threaded openings i and 52 respectively, for attaching a clamp as hereinafter described.

Referring to Figures 1, 2, 3, 4 and 7 it will be observed that the sub-assembly frame iii serves as a support for a drive shaft, generally dcsig= nated 53 which is journaled in the ball bearings ll-4i, the latter in turn being supported by the bearing supports 36-46. Between the bushing journals flt-d'i there is located a worm gear 55 which meshes with a pair of mating sprocket shaft drive gears 56 and 51, which are of equal diameters and of a size such that both will mesh neatly with the worm gear 55. The sprocket drive gear 56 is mounted upon the upper sprocket shaft 58 to which it is pinned by means of the pered pin 59. The shaft 58 is journaled in the lashing 136 and extends through the vertical panel i i of the main frame. Upper sprocket ii and a spacing collar 60 are mounted on shaft 58 the sprocket and collar being fastened to the shait means of set screws 6| and d2, respectiveiy. The lower sprocket driving gear t'i is supported upon the shaft to to which it is likewise keyed by means of the tapered pin Ed.

The shaft likewise extends through the vertical frame panel i i and upon it there is mounted the lower drive sprocket I5 and a drive pulley S5. The pulley is attached by means of 'a- 'set screw 86 and the drive sprocket I5 is attached by means of a set screw 68. The pulley as serves as a drive pulley for a belt, not illustrated, extending to the lower film reel on which the film is wound after projection.

Referring to Figures 1, 3 and 7, in the v notches 49 and 50 there are placed a pair of axially aligned hardened steel pins I2 and F3. The pins rest in the V groove 09 and 50 and are held in placed by clamping plates 'M'I4, the plates in turn being held in place by screws 15. The pins I2 when in place in the grooves 49-50 are axially aligned and the axis of the pins l2 and I3 is located so as to intersect the axis of the drive shaft 53. The pins 12-13 serve as a mounting for a shuttle generally designated 16, Figures 2, 4 and '7, which has a central aperture 11, a top arch ill, a bottom arch I9 and an offset portion 80' having the aperture 8| therein through which the picture is projected. The offset portion 80 is provided with film engaging claws 82. The top arch 18, Figure 7, is provided with a slide bearing 83 and the bottom arch with a slide bearing 84, the bearing being received on the pins I2 and T3. The shuttle I6 is thus permitted to slide vertically on the pins 12-13 and also to rotate about said pins.

The central aperture I1 of the shuttle I6 has parallel horizontal cam engaging surfaces 85 and 8B, Figure 4, with which a cam 89, mounted upon drive shaft 53, cooperates. As the shaft 53 rotates the cam 89 moves the shuttle 16 up and down in an oscillating motion in a vertical direction. The cam 89 is shaped so as to have a constant trans-axial dimension D across any line running through the center of shaft 53, this dimension being equal to the spacing between the cam engaging surfaces 86 and 86 of the shuttle, proper clearance for free action being provided. Thus, as the shaft 53 rotates the shuttle is moved up and down.

The in and out motion of the shuttle for the purpose of moving the claws 82 toward and away from the film and thus into and out of engagement with the perforations of the film is provided by a second cam generally designated 90. Cam, all, Figure l, is mounted upon and rotates with the drive shaft 53. The shuttle is provided with a suitable cam engaging button 92 which rides upon the cam 90 and hence as the drive shaft rotates the shuttle is oscillated slightly about the axis of the pins 'I2-'l3.-

Upon the bearing cap near worm gear 55, Figures 1 and 7, there is mounted a bracket 90 which serves to support the tip end 94 of a tubular member 95 which is provided with an internal spiral spring bearing against a tube 96 which slides in the tube 95. The tube 86 is likewise provided with a tip 01 which is inserted in a suitable aperture 58 in the shuttle. Thus, the spring member or lever 9596 serves to rotate the shuttle in a direction so as to maintain the cam engaging button 92 constantly in engagement with the cam t0.

Immediately against cam 80 there is provided a shutter Md, and at the rear end of the shaft 53 there is provided a v-belt pulley 99 upon which a V belt Gilli is adapted to operate. The v belt extends into the base of the machine to a motor pulley I0l, Figure 2.

To the upper part of the vertical main frame panel II there is attached a reel supporting bracket generally designated I02 having downwardly protruding spaced bearing brackets I03 which are provided with bushings I04 and I05.

go The bushing 505 is apertured to receive a rounded detent rod I06 which is pressed into place by means of a leaf spring WI. The bushings I04 and l05 serve to support a shaft I08 which is provided with'a detent groove I09 and a detent edge IIO. Upon the shaft is mounted a gear III which in Figure 4 is out of mesh with the upper sprocket drive gear 56, and a combined knob and pulley II2 which is attached to the shaft I08 by means of screw Hi. When the knob-pulley I I2 is drawn to the right as shown in Figure 4, the

entire shaft I08 moves, thus forcing detent I08 out of the groove I09 and against the edge IIO, thus maintaining the shaft in position such that the gear III meshes with 'gear56. In this position the knob-pulley H2 is rotated and serves as a drive for rotating the upper film reel, not illustrated, for rewinding purposes.

In a moving picture projector of the intermittent feed type, the most rapidly moving parts are the shuttle and its actuating mechanism, and these parts are subject to the maximum amount of wear and require most frequent servicing. By means of the sub-assembly frame 3| of the present invention, the entire film progressing mechanism mounted thereon may very conveniently be removed for servicing or replacement. Thus, frame 3| which is held in place by only three screws, viz, screws 34, may be removed in either of two fashions for servicing or replacement. Where it is desired not to disturb the sprockets I5--I'I and the remaining apparatus on the lens block side of the frame panel II, the removal is accomplished by removing gears 56 and 51 from their shafts, which is done by simply removing the tapering pins 59 and 64. The gears 50 and 51 are then slipped oi! their shafts 58 and 68, re-

spectively, and then by removing screws 34 and the V belt I00, the entire film actuating mechanism sub-assembly may be lifted off as a unit and a repaired or a new or replacement unit inserted. The unit thus removed appears as in Figure 7 and includes the shaft 53, the worm gear 55, bearing cap 40, bearings ll, cams 8! and 90, the shuttle l6 and the-pulley 99, as well as the light shutter H4 which is mounted on the shaft 52 immediately behind the cam 88. The entire unit may thus be taken to the bench for repair or simply a replacement unit inserted in the projector. The projector may thus be kept in service with a minimum of servicing interruption. Alternatively, where desired, the upper film sprocket l1 and spacer 60 may be removed by loosening their set screws GI and 62, respectively, and the lower film sprocket l and pulley 65 removed by loosening set screws 68 and 66. When this is done the film feeding assembly may be removed by simply withdrawing the screws 84 and in this case the sprocket shafts 58 and 63 as well as the sprocket drive gears 56 and 51 are likewise removed from the machine.

By either method of servicing the entire replacement and servicing operation can be accomplished in a few minutes time.

As many apparently widely different embodiments of this invention may be made without de-.

parting from the spirit and scope thereof, it is to be understood that I do not limit myself to the specific embodiments herein except as defined by the appended claims.

What I claim is:

1. In a motion picture projector, a main support having an upright wall extending in the direction of the projection axis, a sub-frame removably mounted on one side of said wall, a main shaft rotatably mounted on said sub-frame and extending substantially in the same direction as said axis, cam means on said main shaft, a shutter on said main shaft, two transverse sprocket shafts rotatably mounted on said sub-frame above and below said main shaft, said sprocket shafts extending through apertures in said wall. sprockets on said sprocket shafts. on the other side of said wall, means on said sub-frame connecting said sprocket shafts to be driven by said main shaft, a claw feed device mounted on said sub-frame in operative association with said cam means, a projection lens assembly mounted on said other sideof said wall at a level intermediate said sprockets and means for guiding the film between said sprockets past a projection aperture rearwardly of said lens assembly, said wall being apertured rearwardiy of the lens assembly to permit said shutter to extend through said wall into the projection light path and permit said claw feed device to extend through said wall film feed and shutter parts mounted on it, including the sprocket shafts, may be removed as a unitary sub-assembly from the projector.

3. In the motion picture apparatus defined in claim 1, said drive connection between the main and sprocket shafts comprising a gear on the main shaft and a gear on each sprocket shaft meshed with said main shaft gear, said sprocket shaft gears being removable from the end of the sprocket shafts opposite the sprockets whereby upon removal of said sprocket shaft gears the entire sub-frame with the intermittent feed and shutter parts mounted on it may be removed as a unitary subassembly from the projector, leaving the sprocket shafts and sprockets undisturbed.

4. In the motion picture projector defined in claim 1, bearing sleeves in which said sprocket shafts are rotatably supported rigidly mounted on said wall at the sprocket shaft apertures and projecting from said one side of said wall, and apertured bosses on said sub-frame through which said sleeves project whereby said sleeves also serve to locate the sub-frame in its assembly with said wall.

5. In an intermittent feed mechanism for a motion picture apparatus, a rotatable shaft, a rigid shuttle member extending transversely of said shaft having pivot and slide guide mountings both above and below said shaft enabling said shuttle member to rock about an axis intersecting the axis of said shaft and slide parallel to said rock axis, a film engaging claw, tooth on said shuttle member projecting in the direction of said shaft axis, a cam on said shaft adapted during rotation of said shaft to reciprocate said shuttle member parallel to said rock axis, a second cam on said shaft and resilient means maintaining engagement between said second cam into engagement with the film between said sprockets for intermittently advancing said film past the projection aperture.

2. In the motion picture projector defined in claim 1, said sprockets being removably mounted on said sprocket shafts whereby. upon removal ofsaidsprocketstheentiresub-frame andtho and said shuttle member for rocking said shuttle member about said rock axis in synchronism with said reciprocation for positively inserting and withdrawing said claw with respect to the film sprocket holes, said resilient means comprising a levercomprising a pair of telescoped members connected by an external spring that tends to axially separate them, and said lever being maintained under axial compression between a stationary part of the apparatus and the end of said shuttle member remote from said claw.

ROY A. CLAPP.

REFERENCES orran The following references are of record in the 

